1. Field
The presently disclosed subject matter relates to semiconductor light-emitting apparatuses in which light emitted from a semiconductor laser device is wavelength-converted by a wavelength converting board, and to vehicle headlights using the semiconductor light-emitting apparatuses. More particularly, the disclosed subject matter relates to reliable semiconductor light-emitting apparatuses having favorable optical characteristics, which can be used for a vehicle headlight with a simple structure, and to the vehicle headlights using such light-emitting apparatuses.
2. Description of the Related Art
Semiconductor light-emitting devices, in which a part of light emitted from a semiconductor light-emitting chip is converted into light having a different wavelength by a wavelength converting layer and in which a mixture light including the light having the different wavelength mixed with the light emitted directly from the light-emitting chip is emitted, have been used as a light source for various lighting units. In this case, semiconductor light-emitting devices, in which the semiconductor light-emitting chip may be located at a desired position by using an optical fiber, have also been known.
Conventional semiconductor light-emitting devices including a wavelength converting layer and an optical fiber are disclosed in Patent Document No. 1 (Japanese Patent Application Laid Open JP2010-165834). FIG. 7 is a schematic enlarged side cross-sectional view showing a conventional semiconductor light-emitting device, which is disclosed in Patent Document No. 1.
The conventional semiconductor light-emitting device 100 includes: a stem 112 having a base 113, a body 114 and leads 115; a semiconductor light-emitting chip 110 attached to the body 114 of the stem 112 and being electrically connected to the leads 115 of the stem 112; a cap 116 including a window 117, and covering the semiconductor light-emitting chip 110 so that light emitted from the semiconductor light-emitting chip 110 transmits the window 117; a holder 120 including a lens 125 and a hole 122, which may pass through the light emitted from the semiconductor light-emitting chip 110; a supporting member 140; a fixing member 150 located on the supporting member 140; a sleeve 160 attaching the supporting member 140 along with the fixing member 150; and a wavelength converting material 130 attached on the supporting member 140 and attached to the fixing member 150 via a welding 170.
Accordingly, the conventional semiconductor light-emitting device 100 may emit a mixture light including a part of light emitted directly from the semiconductor light-emitting chip 110 with light having a different wavelength wavelength-converted by the wavelength converting material 130 using another part of the light emitted directly from the semiconductor light-emitting chip 110. In this case, when a blue LED chip is used as the semiconductor light-emitting chip 110 and when the wavelength converting material 130 contains a yellow phosphor such as YAG, the conventional semiconductor light-emitting device 100 may substantially white light by an additive color mixture of an excited yellow light emitted from the yellow phosphor and a part of the blue light emitted from the blue LED chip, and therefore may used as a light source for a vehicle headlight, etc.
When semiconductor light-emitting devices including a light-emitting chip are employed as a light source for vehicle lamps such as a headlight, a position light, a room light, etc. the vehicle lamps may generally require optical devices such as a reflector, a diffusing lens, a projector lens and the like to provide a prescribed light distribution. Hence, it may be preferable for the vehicle lamps to form the optical devices in a small size with a simple structure, and also it may be preferable for the optical devices to from the semiconductor light-emitting devices in a small size with a simple structure such that is easily attached to the optical devices.
In addition, when semiconductor light-emitting devices are employed as the light source for the vehicle lamps such as the headlight, the headlight must emit a large amount of strong lights having a substantially white color tone by using an additive color mixture of an excited yellow light emitted from the yellow phosphor and a part of the blue light emitted from the light-emitting chip, so as to brightly illuminate roadway surfaces under various conditions such as a rainy weather, a misty roadway surface, etc.
In the above-described conventional semiconductor light-emitting device 100, after the wavelength converting material 130 is placed on the supporting member 140 while the material 130 is surrounded by the fixing member 150, the wavelength converting material 130 may be attached on the supporting member 140 and to the fixing member 150 via the welding 170. Accordingly, the wavelength converting material 130 may be subject to a misalignment with reference to light emitted from the semiconductor light-emitting chip 110 because of said fixing process of the wavelength converting material 130.
In this case, the semiconductor light-emitting device 100 may emit light having a slightly color variation with respect to prescribed white color light due to the misalignment with reference to the light emitted from the semiconductor light-emitting chip 110. However, the headlight, in which the semiconductor light-emitting device 100 having such a structure is combined with the optical devices such as the reflector, the projector lens and the like, may emit the strong light having a considerable non-uniform white color tone toward the road because the light having a slightly color variation is enlarged by the optical devices and may be projected toward the road.
Therefore, the headlight using the conventional semiconductor light-emitting device 100 may continuously not provide drivers with clear road conditions to drive safely at night. Additionally, the conventional semiconductor light-emitting device 100 may not necessarily become a simple structure as described above.
The above-referenced Patent Documents and additional Patent Documents are listed below, and are hereby incorporated with their English abstracts in their entireties.    1. Patent Document No. 1: Japanese Patent Application Laid Open JP2010-165834    2. Patent Document No. 2: U.S. Pat. No. 8,860,061    3. Patent document No. 3: U.S. patent application Ser. No. 14/745,402    4. Patent document No. 4: U.S. Pat. No. 9,147,814
The presently disclosed subject matter has been devised to consider the above and other problems, features, and characteristics in the conventional art devices. Embodiments of the disclosed subject matter can include reliable semiconductor light-emitting apparatuses that can emit mixture lights having favorable optical characteristics such as a high uniform color tone, a high light-emitting intensity and the like, which can be used for a vehicle lamp and the like, and which can also include an optical fiber. Accordingly, the semiconductor light-emitting apparatuses can emit the mixture lights including a substantially white color tone having a high light-emitting intensity from a small light-emitting surface, which can be used for lighting units such as a vehicle headlight that controls light emitted from the light-emitting apparatus using a reflector and/or a projector lens. The disclosed subject matter can also include a vehicle headlight using the semiconductor light-emitting apparatuses that can form a favorable light distribution pattern with a simple structure.